Integrated automobile fluid servicing apparatus

ABSTRACT

A fluid servicing apparatus for exchanging fluids with a power steering fluid reservoir including drain and supply conduits with inline pumps coupled to a control board on a cabinet housing new and used fluid receptacles and a remote pump actuator in communication with the control board including a switch selectively operable to actuate either of said pumps to drain and fill the reservoir.

This application is a divisional of co-pending U.S. patent applicationSer. No. 10/280,855, now U.S. Pat. No. 6,722,398, filed on Oct. 25,2002, and entitled Integrated Automobile Fluid Servicing Apparatus,which in turn claims the benefit of U.S. Provisional Application No.60/350,157, entitled Remotely Operated Vehicle Fluid Exchange System,filed on Oct. 29, 2001, which are hereby incorporated by reference intheir entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of vehicle maintenance, andmore specifically, to servicing automatic transmission and powersteering fluid subsystems.

2. Background

Each of the numerous fluid subsystems in conventional automobilesrequire frequent servicing by exchanging used up or broken down fluidwith fresh fluid to maintain such subsystems and thus the vehicle in topworking condition and extend the life of the subsystem components andassociated vehicle. In servicing these subsystems, such as thetransmission fluid, engine oil, power steering fluid, engine cooling,and hydraulic fluid, it is often desirable to replace the correspondingfluids in each of these components at the same time either in accordancewith a preferred maintenance plan, out of convenience, or of necessity.Two of the more common fluids requiring replacement at the same time arethe automatic transmission fluid and the power steering fluid.

Initial attempts at fluid servicing devices were dedicated to exchangingfluid with a particular fluid subsystem. For instance, examples of powersteering fluid exchangers may be found in U.S. Pat. No. 5,415,247 toKnorr and U.S. Pat. No. 6,035,902 to Dixon. As pointed out in the Dixonpatent, an operator using of the Knorr device may damage the powersteering pump due to the placement of the hose ends in the powersteering fluid reservoir. Moreover, as the Dixon patent points out, itis preferable to turn the steering wheel of the vehicle during the powersteering fluid exchange procedure due to delivering fresh power steeringfluid into the upper portion of the fluid reservoir and withdrawing usedfluid from a lower part of the fluid reservoir. However, the devicesdescribed in these patents do not appear to allow the operator suchremote control facilitating the wheel turning procedure whilemaintaining command of the pumps. In addition both the devices in theKnorr and Dixon patents include open ended hoses to place in the powersteering fluid. Thus, when the pumps are deactivated and the hoses areremoved from the power steering reservoirs, the remaining fluid in thehoses often spilled adding to undesirable clean up time.

While the Knorr patent indicates that other fluid subsystems may beserviced, the use of such devices for say, servicing an automatictransmission would be unsatisfactory due to the lack of flow controlfeatures. For example, attempts to use the Knorr device to service thetransmission fluid compartment would run the risk of damaging thetransmission pump as well. Thus, it is unlikely that these devices wouldbe used for other than servicing power steering fluid reservoirs andthat additional fluid servicing machines would be necessary to carry outthe servicing procedures of other fluid reservoirs in the vehicle.

Thus, while many of these devices have proven satisfactory in theirperformance for servicing a particular fluid reservoir, multiplemachines are typically required to service more than one fluid subsystemthus adding time as the service technician had to couple and decouplemultiple machines in order to service more than one subsystem. Asmultiple units were required, the service room floor required morestorage space for the machines when not in use.

One such device attempting to alleviate this problem can be found inU.S. Pat. Nos. 5,806,629 and 5,853,068, both to Dixon et al. However,such device incorporates an overly complex motor pump unit andassociated plumbing components adding to the overall expense of themachine.

While many of these devices have proven satisfactory in theirperformance there remains a push for reducing the number of components,cost of manufacture, and reduced assembly time while maintaining thecapability to perform the desired procedures. What is needed is a fluidchanging apparatus configured to conveniently address the needs of thefluid change operator in servicing the various fluid reservoirs in anautomobile using an integrated fluid servicing apparatus having arelatively minimal component fluid transfer system, something theprevious attempts have failed to achieve up to this time.

SUMMARY OF THE INVENTION

In accordance with an embodiment of the present invention, an apparatusand method for performing fluid exchange servicing functions for avehicle is described herein and more particularly for servicing thetransmission and power steering components of a vehicle system. Suchservicing apparatus generally includes a used fluid receptacle coupledto a drain circuit having a drain pump and first extension for placementinto a power steering fluid reservoir and a fresh fluid source coupledto an elongated supply circuit having a supply pump and a secondextension for placement into said power steering fluid reservoir aswell. Such pumps, receptacle, and source are carried on a portablecabinet including a control board coupled to said pumps and a remotepump actuator having at least one switch selectively operable to actuateeither of said pumps from a location remote to said cabinet to drain andfill said power steering fluid reservoir.

In another aspect of the present invention, either of said drain orsupply circuits includes a valve selectively operable to open and closethe associated circuit.

Another feature of the present invention is the incorporation a modeselection switch including at least one mode for servicing a powersteering fluid reservoir and an alternate mode for servicing analternative fluid reservoir.

In yet another aspect of the present invention a method for exchangingfluid with said power steering fluid reservoir using a remote actuatingdevice is provided.

Other aspects of the present invention will become apparent with furtherreference to the following drawings and specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a right front perspective view of a preferred embodiment ofthe automotive fluid servicing apparatus of the present invention;

FIG. 2 illustrates an exemplary control panel, in enlarged scale,included in the automotive fluid servicing apparatus shown in FIG. 1;

FIG. 3 is a right front perspective view, in enlarged scale, of anexemplary manifold incorporated in the automotive fluid servicingapparatus shown in FIG. 1;

FIG. 4 is a schematic of an exemplary plumbing circuit for withdrawingused fluid from a power steering reservoir of a vehicle in analternative embodiment of the automotive fluid servicing apparatus ofthe present invention;

FIG. 5 is a schematic of an exemplary plumbing circuit for adding newfluid to a power steering reservoir of a vehicle in an alternativeembodiment of the automotive fluid servicing apparatus of the presentinvention;

FIG. 6 is a schematic of an exemplary plumbing circuit for performingservicing procedures in accordance with a preferred embodiment of theautomotive fluid servicing apparatus shown in FIG. 1;

FIG. 7 is a schematic of an alternative plumbing circuit for performingservicing procedures in accordance with an alternative embodiment of theautomotive fluid servicing apparatus of the present invention;

FIG. 8 is a partial sectional view taken from the plumbing circuit inFIG. 6 illustrating an exemplary recirculation/bypass fluid path;

FIG. 9 is a partial sectional view taken from the plumbing circuit inFIG. 6 illustrating an exemplary dump fluid path;

FIG. 10 is a partial sectional view taken from the plumbing circuit inFIG. 6 illustrating an exemplary drain fluid path;

FIG. 11 is a partial sectional view taken from the plumbing circuit inFIG. 6 illustrating an exemplary supply fluid path;

FIG. 12 is a perspective exploded view, in enlarged scale, of themanifold illustrated in FIG. 3;

FIG. 13 is a partial sectional view taken from FIG. 7 illustrating aplumbing segment for accommodating a reverse hose flow configuration;and

FIG. 14 is a partial sectional view taken from FIG. 7 illustratinganother plumbing segment for accommodating a reverse hose flowconfiguration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIGS. 1, 3 and 6, an exemplary embodiment of anautomotive fluid servicing apparatus, generally designated 20, of thepresent invention is illustrated. In general, such fluid servicingapparatus is incorporated in a convenient, portable wheeled cabinet 22housing a plumbing subsystem and an electrical command subsystemcooperating to drain fluid from a serviceable component, add fluid tothe serviceable component, circulate fluid between the serviceablecomponent and the apparatus, and drain collected or other stored fluidusing a single, common pump 24 and an integrated manifold assembly 26 asdirected by a service technician and controlled by aprocessor/controller 28.

Plumbing Subsystem

Turning to FIGS. 3, 6, and 12, at the heart of the plumbing subsystem isthe integrated manifold assembly 26 housing a fluid circuit 30 formed ina rectangular manifold body 31 having a top side 33, opposing bottomside 35, rear side 37, front side 43, and two opposing ends 45, 47. Thebody sides and ends have generally planar surfaces cooperating to form arectangular block measuring about six inches wide by three inches deepby three inches high and defining a number of manifold ports forconnecting to various conduits and other hydraulic components. In thisexemplary embodiment, there are six conduit ports.

With particular reference to FIG. 12, an exhaust port 32, a return port34, a drain port 36, and a fresh fluid supply port 38 open outwardly onthe rear side 37 of the manifold body 31. While each of these ports areshown on the same side of the manifold body in FIG. 12, it will beappreciated that the ports may be placed at other suitable locations onthe manifold body. For instance, these same manifold ports are shown ondifferent sides of the manifold body 31 in FIG. 6 for ease ofdescription and clarity and may also provide suitable port locations andis not meant to be limiting in any manner. Other suitable locations willoccur to one of ordinary skill in the art. Each manifold port isthreaded for coupling with one end of a respective conduit, hose, orother suitable tubing or piping, which are in turn connected to adesired source or destination. For ease of assembly, it is preferable tothread one portion of each hose coupling into the respective threadedport opening. The threaded coupling component is constructed to allowthe assembler to merely press the free end of the selected conduit intothe complementary coupling component threaded into the port. Suitablecouplings of this type are available from Parker Hannifin under theTrueSeal trade name.

More specifically, with reference to FIGS. 3, 6, and 12, a used fluidconduit 39 connects between the drain port 36 and a used fluidcollection tank 40 to carry fluid therebetween. Similarly, the freshfluid supply port 38 connects via a new fluid supply conduit 41 to a newfluid tank 42. Such used fluid collection tank 40 is constructed to holda sufficient amount of used fluid to accommodate at least complete drainprocedure and preferably more. The new fluid tank 42 is typicallyconstructed to hold a sufficient volume of fresh fluid to accommodate asingle fill procedure and preferably has a greater capacity as well.This fresh fluid source 42 may be filled through a fill hole (notshown). As it is preferred that the servicing apparatus maintain aportable capability, the used and new fluid tanks are preferably mountedinside the cabinet 22 (FIG. 1) which is sized to accommodate thepreferred tank capacities. It has been found that a 24 quart capacityfor both the new and used fluid tanks accommodates most servicingprocedures.

With continued reference to FIGS. 3, 6, and 12, further convenience isprovided by a set of servicing hoses, 44 and 46 respectively forconnecting between the return port 34 and the exhaust port 32 of theservicing apparatus 20 and the influent line and effluent line of theserviceable component such as an automatic transmission as is well knownto one of ordinary skill. The use of conventional adapters is alsocontemplated if necessary. The connectors illustrated in FIG. 3 areexemplary and not meant to be limiting in any manner as other suitableconnectors will occur to one of ordinary skill. Such connection placesthe transmission in fluid communication with the servicing apparatus 20as will be discussed below. The manifold body 31 further includes asuction port 50 and a pressure port 52 located on the top side 53 of themanifold body (FIG. 12). These ports are also threaded for receiving onepart of corresponding suction and pressure hose couplings 54, 56, whichare connected at their opposite ends to the respective suction (inlet)and pressure (outlet) sides of the pump 24 to place the pump in fluidcommunication with the manifold body 31. Such suction and pressure hosesalso incorporate press-in connectors for convenience of the assembler.

Still referring to FIG. 6, added to the fluid circuit 30 are a number ofpathways formed in the manifold body 31 as well as a number of flowcontrol and filtering components for routing fluid entering and exitingthe manifold between the various fluid ports 32, 34, 36, 38, 50 and 52.Referring now to FIGS. 6 and 8–11, in this exemplary embodiment, thereare four such pathways including a drain path, generally designated 57,for flow of fluid as indicated by directional arrow 58 (FIGS. 6 and 10),a recirculation path, generally designated 80, for flow of fluid asindicated by directional arrow 59 (FIGS. 6 and 8), a supply path,generally designated 93, for fluid flow as indicated by directionalarrow 61 (FIGS. 6 and 11), and a dump path, generally designated 95, forfluid flow as indicated by directional arrow 63 (FIGS. 6 and 9).

It will be appreciated that the manifold body 31 forms a threedimensional fluid circuit and that FIGS. 6 and 8–11 are represented in atwo-dimensional layout for ease of description and are not meant to belimiting in any manner. For instance, the fluid ports in FIG. 12 areshown on one side of the manifold body while the same ports are shown onmultiple sides of the manifold body in FIG. 6. In addition, in FIG. 6,the manifold body 31 is not depicted as a rectangular block as in FIG.12. These illustrations are merely to facilitate description of thepreferred embodiment. Other suitable port locations and pathways mayoccur to one of ordinary skill and still fall within the scope of thepresent invention.

With continued reference to FIGS. 6 and 8–12, each pathway 57, 80, 93,and 95 is generally tubular in transverse cross section and made up ofadjacent passage segments bored into the manifold body 31 which areconfigured with straight runs meeting at right angles and compacted tominimize the size of the manifold body and further reduce hose lengthrequirements between components coupled to the manifold body and overallhose length requirements of the servicing apparatus. Some of these rightangle segments project into or out of the plane of the paper and may notbe shown in FIGS. 6, or 8–11. It will also be appreciated, whenconsidered from end to end, portions of each pathway may extend outsidethe manifold body and include couplings or connectors of flexible orrigid material connected to one or more manifold ports.

With particular reference to FIGS. 6, 10, and 12, during a drainprocedure as will be discussed below, fluid is normally directed in thedirection of arrow 58 through the drain path 57 from the return port 34to the used fluid drain port 36 which may be connected to the used fluidcollection tank 40 via conduit 39. Such passage 57 is formed by an entrybore extending into the manifold body 31, viewed into the paper in FIG.6, from the return port 34 to enter a short pre-filter segment 64 whichturns downwardly at a right angle from the entry bore, toward anaperture (not shown) in the bottom side 35 of the body aligned with afluid entrance into an in-line filter 60 to direct fluid into thefilter. The filter 60 is coupled to a hollow, threaded nipple 67projecting from the bottom side 35 of the manifold. The nipple isscrewed into an opening in the bottom side of the manifold body andfurther extends outside the body providing a connective threaded stubfor the filter 60. After exiting the manifold through the bottomaperture to enter the in-line filter 60, the drain path 57 then reentersthe manifold body through the hollow nipple and projects upwardly intothe body into a pre-drain valve segment 69. About the midpoint of thebody 31, the pre-drain valve segment terminates at an inlet of atwo-position drain/bypass solenoid valve 70 which may be screwed into athreaded valve port 65 on the top side 33 of the manifold body 31 toposition the dual outlet valve 70 in line with both the drain path 58and recirculation path 80 of the fluid circuit 30. Such valve 70includes a drain position, indicated by directional arrow 66, whichdirects fluid entering the inlet of the solenoid 70 out of a drainoutlet of the solenoid 70 and through the remainder of the drain path 58(FIGS. 6, 10) and a normally open bypass position, indicated bydirectional arrow 68, which directs fluid entering the inlet of thevalve 70 out of an alternate outlet and through a recirculation path 80(FIGS. 6, 8).

The valves described herein are preferably two-position, three-waymagnetic solenoid valves, either size 8 or 10, which may be energized toenter into a number of alternative positions. Such valves are availablefrom Hydac Technology Corporation in Bethlehem, Pa. Other suitablevalving arrangements for directing fluid flow to or from multiplechannels may also be used.

With continued reference to FIG. 10, the drain path 57 turns at a rightangle from the longitudinal centerline of the solenoid 70 into apost-solenoid segment 72 forming the stem of a T-shaped intersection 74.Then the path is bifurcated to, in one branch, enter into a used fluidconnection branch 75 of the T-shaped intersection leading to the drainport 36 which may be connected to the used fluid collection tank 40.Fluid entering the return port 34 from the serviceable component is thusnormally directed along this drain path 57 if the drain/bypass solenoid70 is energized to the drain position 66 for collection in the usedfluid tank 40.

Referring now to FIGS. 6 and 8, when the drain/bypass valve 70 isenergized to the bypass position as indicated by directional arrow 68,the recirculation path 80 is opened and the drain path 57 is blocked.The recirculation path 80 shares the same plumbing with the drain path57 up to the drain/bypass solenoid 70 including the return port 34,pre-filter segment 64, filter 60, and pre-valve segment 69. Continuingthrough the drain/bypass solenoid valve 70, when energized to the bypassposition 68, the recirculation passage 80 projects at a right angle tothe longitudinal centerline of the solenoid to form an L-shapedrecirculation loop leading to the exhaust port 32 which may be connectedto the transmission inlet. Fluid entering the recirculation path fromthe return port 34 is directed through the solenoid 70 set in the bypassposition 68 to exhaust port 32. Such recirculation path normally servesto circulate fluid in the direction indicated by arrow 59 between theserviceable component and the servicing apparatus and through the filter60 while bypassing the pump 24, used fluid tank 40, and new fluid tank42.

With continued reference to FIG. 6, and with particular reference toFIG. 11, the fresh fluid supply passage 93 is formed by an entry boreextending into the manifold body 31 from the new fluid supply port 38 tothen turn at a right angle forming an L-shaped pre-supply valve segment82. The segments discussed herein are preferably bored into the manifoldbody during manufacture. Such segment terminates at a two-positiondump/supply solenoid valve 84 which is also screwed into a threaded port85 on the top side 33 of the manifold body 31 to position the valve 84in line with the new fluid supply passage 93 (FIG. 11) and the dumppassage 95 (FIG. 9) in the fluid circuit 30. Such valve 84 includes anormally open supply position, indicated by directional arrow 81, whichreceives fluid withdrawn from the new fluid supply tank 42 and directsit through the remainder of the supply path 93 (FIG. 11). Thesupply/dump valve 84 also includes a dump position, indicated bydirectional arrow 83, which receives fluid being dumped from the usedfluid tank 40 and directs such fluid on through the remaining portion ofthe new fluid supply passage as well (FIG. 9).

Continuing with the new fluid passage 93, a pre-suction port segment 86projects at a right angle to the longitudinal centerline of the solenoid84 and further includes a second right angle turn leading to the suctionport 50 (FIGS. 6 and 11). The suction side hose 54 connects the suctionport to the suction side of the pump 24 and a pressure side hose 56connects the pressure side of the pump 24 with the pressure port 52 atthe top side 33 of the manifold body 31 to position the pump 24 in linewith the supply path 93 (FIG. 11) and also the dump path 95 (FIG. 9)depending on the valve 84 position. Reentering the manifold body 31through the pressure port, the new fluid supply passage 93 projectsdownwardly through a pre-supply filter segment 87 to lead to an aperture(not shown) on the bottom side of the manifold body 31 aligned with anentry hole in a supply filter 88. The supply filter 88 is also connectedto the manifold body via a hollow, threaded nipple 90 on the under side35 (FIG. 12) similar to the drain filter 60 connection. Exiting thefilter 88 through the hollow nipple 90, the new fluid supply path 93projects upwardly into the manifold body 31 through an in-line one-waycheck valve 92 and then turns outwardly toward the back side 37 of themanifold body in an L-shaped segment 94 leading to the exhaust port 32which may be connected to the transmission inlet or collection tank viaservicing hose 46. The final segment 94 of the new fluid supply path 93leading to the exhaust port 32 is common with the last segment of therecirculation path 80.

The check valve 92 is incorporated in the supply fluid circuit 93 toprevent fluid from backflowing or otherwise entering the outlet of thesupply filter 88 from the recirculation path. This feature also servesto keep the pump 24 primed in use. However, it is preferable to select asuitable pump 24 having an integrated check valve for incorporation intothe servicing apparatus 20 so that the external check valve 92 can beomitted altogether. The supply pathway 93 normally serves to conductfluid in the direction of arrow 61 from the fresh fluid supply 42connected to the new fluid port 38 and direct the fluid to the exhaustport 32 and to the upstream line of the serviceable component viaservicing hose 46 to supply fresh fluid thereto. Alternatively, suchpassage 93 can be used to drain the new fluid tank 42 when the servicinghose 46 is coupled to a collection tank.

Turning now to FIGS. 6 and 9, the fluid circuit 30 also includes theused fluid dump pathway 95 for transporting fluid in the direction ofarrow 63 between the drain port 36 and the exhaust port 32 for drainingfluid from the used fluid tank 40 using the common pump 24. Withcontinued reference to FIG. 9, the dump path 95 begins with at the drainport 36 which is normally coupled to the used fluid collection tank 40via the used fluid conduit 39. The dump path 95 is then formed with abore projecting inwardly from the drain port 36 along a straight segmentto form the first branch 75 of the T-intersection 74. The path 95bifurcates at intersection 74 to flow through to a straight pre-valvesegment 91 to one inlet of the dual inlet dump/supply solenoid valve 84which controls the flow on to the outlet bore 86 (pre-suction portsegment) leading to the suction port 50 when the valve is energized tothe dump position 83. The remaining portion of the dump path is commonto the new fluid supply path 93 as it exits the solenoid 84 ultimatelyleading to the exhaust port 32 including passage through the outlet bore86 through the suction port 50 to the inlet of the pump 24 via coupling54. The fluid is then directed through the outlet of the pump 24 throughcoupling 56 to pressure port 52 on through filter 88, check valve 92 toexhaust port 32. Such path 95 normally serves to direct fluid withdrawnfrom the used fluid collection tank 40 in the direction of arrow 63using the common pump 24 to direct used fluid through the exhaust port32. Instead of connecting the service hose 46 to the transmission,however, the free end of the service hose is typically placed in a wastefluid receptacle (not shown) for future storage so that the used fluidtank 40 may be drained.

With continued reference to FIGS. 6 and 8–11, fluid typically enters thereturn port 34 from conduit 44 connected to the downstream port of thetransmission and exits the exhaust port 32 to be directed through hose46 to the upstream port of the transmission. Fluid is generallycirculated through the fluid circuit 30 by the single, non-reversiblepump 24 interposed in the supply and dump pathways 93 and 95,respectively, to complete these pathways. Fluid may also be circulatedby a pump associated with the serviceable component through the drainand recirculation paths 57 and 80, respectively. Direction of the fluidthrough the fluid circuit 30 is normally determined by the respectivepositions of the single inlet, dual outlet, drain/bypass valve 70 anddual inlet, single outlet, dump/supply valve 84. The drain/bypass valve70 operates to direct fluid entering the return port 34 through thedrain or bypass passages 57 and 80 respectively with one side of thevalve 70 in fluid communication with the return port 34 and the secondside in fluid communication with the drain port 36 and exhaust port 34.When solenoid 70 enters into the drain position 66, the bypass passage80 is blocked off and the passage between the return port 34 and thedrain port 36 is open and fluid may flow in the direction of arrow 58(FIG. 10). On the other hand, when the valve 70 is energized to thebypass position 68, the drain passage 57 is blocked off and the passagebetween the return port 34 and the exhaust port 32 is open establishinga bypass loop 80 wherein fluid may circulate in the direction of thearrow 59 and wherein fluid does not circulate through the pump 24 (FIG.8).

Referring to FIGS. 6, 9, and 11, connected in fluid communication withthe supply and dump paths 93 and 95, respectively, is the dump/supplyvalve 84 with the outlet of the valve in fluid communication with theexhaust port 32 and the dual inlet in fluid communication with the drainport 36 and new fluid supply port 38. When the valve 84 is energized tothe supply position 81, the dump passage 95 is blocked off and thepassage 93 between the new fluid supply port 38 and the exhaust port 32is open so that fluid may flow in the direction of arrow 61 (FIG. 11).On the other hand, when the valve 84 is energized to the dump position83, the new fluid supply passage 93 is blocked off and the passagebetween the drain port 36 and the exhaust port 32 is open establishing apassage 95 for dumping fluid in a direction indicated by arrow 63 to becollected in the used fluid tank 40 by withdrawing such fluid with thecommon pump 24 (FIG. 9). Selection of these valve positions 66, 68, 81,and 83 is directed by the controller 28 and the operator or servicetechnician using the electrical command system as will now be described.

Electrical Command Subsystem

Referring now to FIGS. 1–3, and 6, the heart of the electrical commandsub-system is the controller 28 which is a programmable circuit boardhaving a central processing unit (CPU) and associated memory fortransmitting control commands to the pump 24 or valves 70, 84 inaccordance with command sequences stored in the memory responsive tofeedback transmitted from a number of sensors to direct the fluidservice operations selected by a service technician. In this exemplaryembodiment, there are three such sensors.

With particular reference to FIG. 6, the controller 28 is connected to anew fluid tank sensor 100 and a used fluid tank sensor 102 through theirrespective electrical leads 104 and 106 to provide fluid level feedbackfor each tank, 42 and 40, respectively. The fluid level sensors detectthe fluid level in their respective fluid tanks and provide thisinformation to the controller which includes tank geometric data andfluid density data in its memory for calculating the volume of fluid ineach tank. Such fluid level sensors are preferably gas sensors,available from Motorola and constructed to monitor the air pressure ineach tank. A two-port balancer system is used so that the sensors candetect outside air pressure and take into account elevation of theservicing apparatus to provide more accurate fluid level readingsthereby compensating for discrepancies between sea level readings andreadings taken at other altitudes.

The controller 28 is also in electrical communication with a pressuresensor 108 through electrical lead 110. Such pressure sensor 108 isthreaded into an aperture 109 on the top surface of the manifold body 31and is used for sensing fluid pressure in the last segment 94 of thefluid circuit leading to the exhaust port 32 and providing feedback tothe controller 28 and is primarily used to detect incorrect service hoseconnections during the drain procedure as will be discussed below.

With continued reference to FIG. 6, the pump 24, drain/bypass valve 70,and dump/supply valve 84 are in electrical communication with thecontroller 28 via their respective electrical connectors 112, 114, and116. Using feedback from the sensors and any additional operator input,the controller energizes the first and second valves 70 and 84 to thedesired positions as will be described below and further actuates thepump 24 to on and off states during selected servicing procedures tocirculate the fluid through the fluid circuit 30 from the desired sourceto the selected destination. Conveniently, the controller 28, a controlpanel 130, valves 70 and 84, pump 24, and sensors 100, 102, and 108 arein electrical communication with a set of battery cables 120 (FIG. 1).Thus, power may be supplied to such components capable of being poweredby a 12 volt DC source by attaching a set of battery cables 120 to thevehicle's battery. It will be appreciated that such electrically poweredcomponents could also be hardwired to an alternative power sourcelocated on the servicing apparatus itself 20 or constructed to plug intoa wall outlet.

Referring now to FIGS. 1 and 2, in this exemplary embodiment, anoperator may interface with the controller 28 via a control panel 130located on a top forward inclined surface of the cabinet 22. Suchcontrol panel is generally divided into four regions including anoptions menu listing 132 presenting the available operational options, adisplay region 134 with a plurality of LEDs and a counter display 136for indicating machine and operational status and displaying quantity ordiagnostic information, an interactive control region 138 and a powersteering exchange (PSX) pendant dock region 140 for attaching a remotecontrol for controlling power steering fluid exchange operations whichwill be described in detail below.

With continued reference to FIG. 2, the options menu listing 132positioned to the left side of the control panel 130 includes a listingof procedural options 1–9, respectfully indicated as OP1–OP9 asimprinted or otherwise provided on the face of the control panel (FIG.2). The exemplary options are as follows:

OP1 Add 1 quart of fluid;

OP2 Remove 1 quart of fluid;

OP3 Drain new fluid tank;

OP4 Drain used fluid tank;

OP5 Access new fluid volume;

OP6 Access used fluid capacity;

OP7 Auto prime the system;

OP8 New fluid sensor check; and

OP9 Used fluid sensor check.

Such exemplary options, as illustrated in FIG. 2, are accessible via anoptions menu button 142 in the control region 138 and engageable by astart exchange/options button 144 as will be described below. Thedisplay region 134 provides visual feedback to the operator as to thestatus of the fluid exchange procedures and servicing apparatus 20operation. The primary indicator is the counter display 136 whichprovides a visual display of requested information such as the servicingoption being invoked, fluid capacities, or other information in the formof alphanumeric messages.

Continuing with FIG. 2, further comprising the display region 134 are anumber of LED indicators divided into four columns. The first columnincludes a quarts LED indicator 146 and a liters LED indicator 148. Suchindicators indicate the system of measurement being used. Next to thefirst column is a column of amount indicators including a 20 quartindicator 150, a 16 quart indicator 152, a 12 quart indicator 154, and a4 quart indicator 156. Each of these indicators provides a display tothe operator as to the amount of fluid selected by the operator for anexchange. For purposes of an automatic transmission fluid exchange,eight cylinder, full size vehicles or truck typically require a twentyquart exchange. Mid-size vehicles with 6-cylinders typically require asixteen quart fluid exchange and compact, four cylinder vehiclestypically require a twelve quart exchange. Sub-compact vehiclestypically only require a four quart exchange.

Still referring to FIG. 2, the third column in the display region 134indicates machine operation status and includes a stopped indicator 158,a halted indicator 160, a running indicator 162, a complete indicator164, a switch hoses indicator 166, and a shift to neutral indicator 168.A machine status column is the fourth column in the display region 134.Such machine status column includes a new ATF low indicator 170, a usedATF full indicator 172, an add/remove ATF indicator 174, and a new/usedATF drain indicator 176. The meaning of these indicators will bediscussed below when the operation of the servicing apparatus isdescribed.

Spaced below the display region 134 in the control region 138 is a firstand second set of depressable buttons for initiating a variety offunctions to operate the servicing apparatus 10 (FIG. 2). The leftmostbutton of the first set is a quantity button 178 for selecting thequantity of fluid to be transferred from one location to another.Depressing this button cycles through the quantity indicators 150, 152,154, and 156. Next to the quantity button is positioned theexchange/options button 144 for initiating a fluid exchange orinitiating the option selected by the options menu button 142. A powersteering button 180 for initiating a power steering fluid exchange isnext in line followed by the option menu button 142. The options menubutton cycles through the options listed in the options menu 132 whendepressed.

The leftmost button in the right hand set of buttons is an add ATFbutton 182 for adding automatic transmission fluid where directed by thefluid circuit 30. Next to the add ATF button is a remove ATF button 184.Selection of this button may be used to remove or drain ATF from theselected source. The third button is a cycle sensors button 186 forcycling the valves 70, 84 between their respective positions to clearthe valves prior to operation of the servicing apparatus 20 to ensurethe valves are in proper working order. The last button is a stop button188 for shutting the apparatus down completely in an emergency or otherdesired stop condition. Such button is preferably a larger size orotherwise stands out from the other buttons so it may be rapidly locatedby the operator. An illustrative servicing procedure using theabove-described plumbing and electrical subsystems incorporated into aservicing apparatus 20 will now be described.

Operation of the Fluid Servicing Apparatus

In the field, the manifold assembly 26 is typically secured within aninternal compartment of the servicing apparatus 20 using a suitablethreaded fasteners screwed into a pair of mounting bores 194 on thefront side 43 of the manifold body 31 (FIGS. 1 and 12) and comespreassembled. Such internal compartment is accessible via a removableservicing panel 190. The pump 24 is also preferably secured inside theservicing apparatus. The control panel 130 is also removable and mayprovide an alternative access into the compartment. Near the bottom ofthe servicing apparatus, the used and new fluid tanks 40 and 42,respectively are placed on a convenient shelf.

While the servicing apparatus 20 is typically assembled prior tooperation of the servicing apparatus 20, it will be appreciated that theintegrated manifold assembly 26 has been designed to reduce assemblytime and facilitate servicing in the field and that some connection maybe required prior to initiating servicing procedures or duringmaintenance.

Referring now to FIGS. 3, 6, and 12, starting with the basic manifoldbody 31 with preformed fluid circuit 30 and built-in couplings threadedinto the ports 32, 34, 36, 38, 50 and 52, the operator may connect theused fluid conduit 39 by pressing one end into the drain port 36 and theother end is inserted into or otherwise coupled to the used fluid tank40. The supply conduit 41 is likewise coupled between the supply port 38and the new fluid tank 42. The pump 24 may then be connected to the topside 33 of the manifold body by pressing in one end of the suction hose54 into the suction port 50 and its opposite end into the suction sideinlet of the pump 24. Similarly, one end of the pressure side hose 56 ispressed into the pressure port 52 its other end into the pressure sideoutlet of the pump 24.

With continued reference to FIG. 12, the connector nipples of thevalves, pressure sensor, and filter components may then be screwed intotheir respective threaded ports on the manifold body 31. Morespecifically, the drain/bypass valve 70 is threaded into the port 65 toplace the valve inline with the drain and bypass fluid paths, 57 and 80respectively. The inlet of the valve 70 is aligned with the terminal endof the pre-filter bore 34. The first outlet of the valve 70corresponding to position 66 is aligned with the inlet to bore 72 andthe second outlet of the drain/bypass valve 70 corresponding to position68 is aligned with the inlet to the recirculation loop 80. Likewise, thedump/supply valve 84 is screwed into threaded port 85 on the upper side33 of the manifold body to place such valve in fluid communication withthe supply and dump paths, 93 and 95 respectively. The first inlet ofvalve 84 corresponding to position 81 is aligned with the exit ofpre-valve bore 82 and the second inlet of valve 84 corresponding toposition 83 is aligned with the exit to bore 91. The outlet of valve 84is aligned with the entrance to post-valve bore 86. The nipple of thepressure switch 108 is also threaded into its respective threadedaperture 109 on the top side 33. On the bottom side 35 of the manifoldbody 31, the filters 60 and 88 are screwed onto their respective nipples67 and 90 until their respective gaskets are flush with the undersurfaceof the manifold providing a suitable seal. The entry port of the drainfilter 60 aligns with the aperture occurring at the end of the pre-drainbore 34. The entry port of the supply filter 88 aligns with the apertureoccurring at the end pre-supply filter bore 87. The filters arepreferably of the ten micron absolute variety and the threaded nipplesare preferably constructed using metric threads to inhibit a servicetechnician from bypassing the filters. Such filters also act asmaintenance indicators as fluid servicing procedures will take longer asthe filters become more and more clogged obstructing fluid flow.

Each of the electrical leads of the pump 24, valves, 70, 84, and sensor108 along with the other DC powered components may then be placed inelectrical communication with the controller 28 and battery cables 120via the wiring harness.

When the service technician is prepared to service an automobiletransmission, with reference to FIGS. 1–3, and 6, the new fluid tank 42and used fluid tank 40 may initially be empty. The servicing apparatus20 is initially prepped for servicing by filling a quantity of newtransmission fluid through a fill hole (not shown) into the new fluidtank 42. For purposes of this operational procedure, it will be assumedthat the used fluid tank 40 is initially empty and the new tank 42 hasan adequate supply of transmission fluid to perform a complete exchange.The servicing apparatus 20 is wheeled over near the transmission to beserviced. Using well known procedures, the service technician interruptsthe transmission cooling lines to expose an influent line or inlet portand an effluent line or outlet port and connects the free ends to thereturn and exhaust ports 34 and 32 of the manifold assembly 26 using theservice hoses 44 and 46 using conventional adapters if necessary.Preferably, the technician connects the effluent line of thetransmission to the return port 34 and further connects the influentline at one end to the exhaust port 32 such that the connection placesthe transmission in fluid communication with the fluid passages 57, 80,93, and 95 of the servicing apparatus 20 (FIGS. 1, 6, and 8–11). It willbe appreciated that the service hoses 44, 46 are preferably clearallowing an operator to visually check the condition of the fluid ineach hose. The default position of the drain/bypass valve 70 is thebypass position 68 blocking off the drain path 57 so that fluid flowfrom the transmission will circulate through fluid passage 80 in thedirection of arrow 59 initially when the vehicle engine is turned on toactivate the transmission pump (FIG. 8).

With continued reference to FIGS. 6 and 8, once the service hoses 44, 46are connected, the technician may then connect battery cables 120 to thevehicle battery to supply power to the control panel 130, controller 28,drain/bypass valve 70, dump/supply valve 84, pump 24, sensors 100, 102,108, all of which are preferably selected to run on a 12-volt DC powersupply. Using the versatile servicing apparatus 20, the technician mayperform several servicing procedures including circulation and clean,automatic transmission fluid exchange by draining and refilling thetransmission in incremental steps, draining and refilling thetransmission pan, topping off fluid levels, and draining the new andused fluid tanks. It will be appreciated that the following proceduresare performed using only a single common pump 24 operating inconjunction with the vehicle transmission pump for some procedures.

In the initial stage after the service hoses 44 and 46 are connected tothe return and exhaust ports 34 and 32 and transmission cooling lines,the operator may press the cycle sensors button 186 to actuate thevalves 70 and 84 through their full range of movement to clear anyobstacles, debris, or other contaminants that may prevent performance.

With battery cables 120 connected, the operator may start the vehicleengine to operate the transmission pump and to pressurize fluid out ofthe transmission to begin circulating fluid through circulation passage80. This is commonly referred to as circulation mode during which thepressure switch 108 in normally inactive. Depending on the transmissionpump and direction of fluid flow, used fluid from the transmission isforced out into the recirculation passage 80 from either the return port34 or the exhaust port 32. Fluid will either flow in the direction ofarrow 59 or in a reverse direction. The fluid exits the recirculationpassage 80 from the opposite port wherein fluid is entering and reentersthe transmission through the associated servicing hose. The check valve92 prevents the used fluid from entering the servicing apparatus pump24. At this point a closed circulation loop between the vehicletransmission cooling lines and servicing apparatus 20 is established andthe running indicator 162 lights up on the control panel 130. It will beappreciated that the used transmission fluid is directed through thefilter 60 to remove particulate from the used fluid during this initialprocedure.

While the fluid is circulating, the operator may then select thequantity of fluid to be changed via the control board 130 connected tothe processor/controller 28 by depressing the quantity button 178 untilthe indicator 150, 152, 154, or 156 beside the desired quantityilluminates (FIG. 2). Assuming for example, a full-sized 8-cylindervehicle is being serviced, the operator selects the 20 quart quantity bytoggling the quantity button until the desired indicator lights up. Inthis instance, the 20 quart indicator 150 will light up on the controlpanel. At this point, the pump 24 is not running and fluid is only beingcirculated by the transmission pump.

Turning now to FIGS. 2, 6, 8, and 10, having selected the quantity to beexchanged, the operator presses the start exchange/options button 144 onthe control panel 130 of the servicing apparatus 20, which causesseveral actions to occur. Initially, the controller 28 energizes thedrain/bypass solenoid 70 to move from the bypass position 68 to thedrain position 66 to block off the recirculation passage 80 and open thedrain path 57. If the service hoses have been connected properly, usedfluid entering the return port 34 under pressure from the transmissionpump is directed through the drain path 57, along the direction of arrow58, through the drain port 36 and used fluid conduit 39 connectedthereto to be collected in the used fluid collection tank 40. Once thevalve 70 is energized to the drain position 66, the controller 28 willtake a reading of the used fluid tank sensor 102 to sense thehydrostatic pressure head therein (FIG. 6). If no fluid is sensed in theused fluid tank 40, the controller will also take a reading of thesignal transmitted from the pressure sensor 108 to determine if anyfluid is entering the exhaust port 32 and is present in segment 94. Withthe signal stored showing no fluid in the used fluid tank, detection offluid entering through the exhaust port 32 into the recirculationpassage 80 is indicative of an improper hose connection. If that's thecase, the processor 28 acts accordingly to alert the operator of animproper hose coupling condition by transmitting a signal to illuminatethe switch hoses indicator 166 on the control board 130. It will beappreciated that an audible alarm may be programmed into the controller28 to accompany this display or any of the displays to further alert theoperator. The operator may then turn the vehicle engine off and manuallyswitch the service hoses 44 and 46 between the respective ports 32 and34. Once the hoses are switched the operator restores the servicingapparatus 20 to circulation mode as described above.

On the other hand, if a no pressure signal is transmitted by thepressure switch 108 to the processor after the drain process isinitiated and no fluid is detected by the sensor 102 in the used fluidtank 40, the shift to neutral indicator 168 is illuminated. Thisoccurrence may be due to the fact that, for instance, many Chryslertransmissions pump fluid only when in neutral. If the switch hosesindicator 166 and the shift to neutral indicator 168 have not lit, thenthe hoses are connected properly and proper fluid flow has beenestablished. The transmission may then be serviced.

Assuming these error conditions do not occur, when the start button 144is pressed the transmission pump will force the fluid from the returnport 34 through the filter 60 into the drain passage 57 and through thesolenoid valve 70 set in the drain position 66 (FIGS. 6 and 10). Usedfluid passing through the solenoid 70 is directed to the drain port 36in the direction of arrow 58 and expelled into the used fluid tank 40 .The level sensor 102 in the used fluid tank transmits a signalproportional to the level of the fluid entering into the used fluid tankto the processor 28 by sensing the hydrostatic pressure head of thefluid entering the used fluid tank. The pressure head data is used tocalculate the volume of fluid in the used fluid tank as the knownparameters of the tank geometry and fluid density stored in theprocessor are recalled by a volume calculation routine. In thisexemplary embodiment, once 6/10 of a quart is collected in the usedfluid tank 40 as calculated by the processor 28, the processor willenergize the drain/bypass solenoid 70 to reenter the bypass position 68blocking off the drain passage 57 and forcing the fluid into therecirculation passage 80 in the direction of the arrow 59. Otherpredetermined quantities could also be used. The processor 28 theninitiates an incremental fill mode.

Turning now to FIGS. 2, 6, and 11, to perform the incremental fillportion of the process, the processor 28 will actuate the dump/supplysolenoid 84 to cause it to assume the supply position 81 to open the newfluid supply path 93 from the new fluid tank 42 through the servicingapparatus pump 24 to the exhaust port 32 to the transmission viaservicing hose 46. The processor also actuates the pump 24 at this timewithdrawing fluid from the new fluid tank 42 in the direction of arrow61 and through the suction port 50 and suction hose 54 to the pump.Fresh fluid is then pumped out of the pump through the pressure hose 56to pressure port 52. Such fresh fluid is directed under pressure throughthe supply filter 88 and one-way check valve 92 and, because it can notenter the drain/bypass solenoid 70 due to incoming fluid pressure, isdirected through the exhaust port 32 to the vehicle's transmission viaservice hose 46. When the level in the new fluid tank is lowered anamount corresponding with 6/10 of a quart, the level sensor 100 willtransmit a signal to the processor 28 which is programmed to respond toshut off the internal pump 24 and then shift the drain/bypass solenoid70 back into the drain position 66 to repeat the incremental drainprocedure.

This drain then fill process continues in an alternating, iterativemanner as the processor 28 periodically responds to discrete drops inthe level of fluid sensed by the fluid sensor 100 in the new fluid tank.When the quantity of the new fluid transferred out of the new fluid tankequals the preselected quantity initially set by the operator, andindicated by one of the quantity indicators 150, 152, 154, or 156, theprocessor will energize an exchange complete indicator 164 on thecontrol board 130 and actuate an audible signal (FIG. 2). The processor28 then shifts the drain/bypass solenoid 70 to the bypass position 68 toswitch the servicing apparatus 20 to the recirculation mode andcirculates fluid through the recirculation passage 80. As before, duringrecirculation mode, the internal pump 24 is deactivated.

In this exemplary procedure, the processor is operative to, in discrete6/10 quart increments, transfer a total of 20 quarts of fluid to theused fluid tank 40 and an equal volume of new fluid is withdrawn fromthe new fluid tank 42. Responsive to the exchange complete indicator,the operator will turn the engine off and disconnect the service hoses44, 46 from the servicing apparatus 20. The operator will then reconnectthe vehicle transmission cooling loop to complete the servicingprocedure. It will be appreciated that upon the operator depressing thestart button 144, the entire fluid exchange procedure will be performedautomatically without further operator intervention until he or sheturns the engine off and reconnects the transmission cooling lines,assuming no error in connection was detected. In addition, to prevent anoverpressure condition during fluid exchange or other servicingprocedures, a pressure relief valve (not shown) may be placed incommunication with the fluid circuit 30 and set to relieve in responseto a preselected pressure to route overpressurized fluid through abypass. It will be appreciated that the alternating drain and fillexchange process takes place rapidly and an entire exchange for an eightcylinder vehicle can take place in approximately 10–15 minutes.

Such fluid exchange will typically leave the new fluid tank 42 empty orpartially empty and the used fluid tank 40 partially full or completelyfull depending on the tank capacity. Should the operator then attempt tostart another servicing procedure and select an exchange quantity thatexceeds the amount of fluid remaining in the new fluid tank 40, theprocessor 28, having taken a reading of the new fluid sensor 100, willtransmit a signal to the control board 130 to illuminate the new ATF lowindicator 170 to alert the operator that there is insufficient fluid inthe new fluid tank 42 to perform the selected procedure (FIGS. 2 and 6).To refill the new fluid tank 42, the operator may supply new fluidthrough its fill hole. During this procedure, the processor functions toilluminate the Add/Remove ATF indicator 174 alerting the operator thatfluid is being added to the new fluid tank 42.

On the other hand, should the operator select an exchange quantity thatwould overflow the capacity of the used fluid tank 40, the processor,having taken a reading of the used fluid sensor 102, will transmit asignal to the control board 130 to illuminate the used AFT fullindicator 172 alerting the operator to drain the used fluid tank beforeproceeding. Conveniently, the fluid circuit 30 and common pump 24 enablesuch draining or dumping of the used fluid tank 40 without theassistance of a dedicated drain pump.

Referring now to FIGS. 1, 2, and 9, to initiate the used fluid dumpprocedure, the operator will connect one end of the servicing conduit 46to the exhaust port 32 and place the free end of the servicing conduitinto a fluid waste tank (not shown). The operator will then depress theoptions button 142 on the control panel 130 to scroll through theoptions menu (OP1–OP9) until the desired option is displayed in thecounter display 136. In this scenario, the OP4 option code would bedisplayed in the counter display 136 indicating that the operator haselected to drain the used fluid tank. Conveniently, the operator mayrefer to the option menu 132 imprinted on the left side of control panel130 to determine the procedure associated with the option code. Next,the operator may engage the start button 144 to begin the used fluiddumping procedure. In response to the operator's command, the controller28 energizes the dump/supply valve 84 to its dump position 83 to openthe dump passage 95 and then actuates the pump 24 to begin drawing fluidfrom the used fluid tank 40 through the open dump passage in thedirection of arrow 63. The fluid is expelled through the exhaust port 32through the servicing conduit 46 and into the storage receptacle. Oncethe controller 28 detects the used fluid tank is at a predeterminedbottom operating level via the used fluid level sensor 102, thecontroller will shut the pump 24 off and terminate the procedure. Bypressing the start button 144 for five seconds the operator can effectdraining of the used fluid collection tank 40 until the stop button 188is pressed. An audible alarm sounds when the used fluid tank level isempty as sensed by the used fluid sensor 102 and illumination of thecomplete indicator 164 on the control panel 130 alerts the operator thatthe dump procedure is completed. It will be appreciated that theplumbing circuit of the exemplary embodiment enables draining of theused fluid tank without the necessity of inverting the tank upside downto drain from its top end or incorporating an extra dedicated drain pumpto draw the used fluid from the used fluid tank and direct it to a wastefluid collection receptacle.

In a similar manner, the new fluid tank 42 may also be drainedcompletely as desired. Referring now to FIGS. 1, 2, 6, and 11, asdescribed for the used fluid tank 40 dumping procedure, one end of theservicing conduit 46 may be connected to the exhaust port 32 and itsfree end placed into a new fluid storage receptacle (not shown). In thisscenario, the operator may toggle the options button 142 until OP3 isdisplayed in the display counter 136. Activation of the exchange/optionsbutton 144 will cause, the controller 28 to shift the dump/supply valve84 to its supply position 81. The pump 24 is also actuated and fluid isdrawn from the new fluid tank 42 along the supply passage 93 in thedirection of arrow 61 to be expelled through the exhaust port 32. Theexpelled fluid is transferred through the servicing hose 46 to the newfluid receptacle for storage. The processor 28 is responsive to thesensor 100 sensing that the fluid level in the new fluid tank has fallento a predetermined bottom operating level to shut the pump 24 off andterminate the drain new fluid procedure. The operator may then press andhold the start button 144 for five seconds to initiate a full drain ofthe new fluid tank 42 until the stop button 188 is pressed. An audiblealarm sounds when the new fluid tank level is empty as sensed by the newfluid sensor 100 and the complete indicator 164 is illuminated by theprocessor on the control board 130 (FIG. 2).

Turning now to FIGS. 2 and 6, it will be appreciated that the operatormay check the new fluid volume and used fluid capacity as calculated bythe controller 28. To display the new fluid volume in the new fluid tank42, the operator may depress the options button 142 and scroll throughthe options menu until OP5 is displayed in the counter display 136. Theoperator may then simply depress the start exchange/options button 144and the new fluid level sensor 100 sends a signal to the controller 28which processes the signal and displays the new fluid level in thecounter display 136 in the measurement selected (quarts or liters).Likewise, to check the remaining capacity in the used fluid tank 40, theoperator may select OP6 using the options menu button 142 and thendepress the start button 144. The used fluid level sensor 102 willdetect the used fluid level in the used fluid tank 40 and transmit thecorresponding signal to the controller 28. The signal is processed andthe remaining capacity is calculated and displayed on the counterdisplay 136. These features may be used by the operator prior toinitiating a servicing sequence or in response to an indicator lightfrom the control panel concerning fluid levels or any other time asselected by the operator.

With continued reference to FIGS. 1 and 6, prior to beginning aservicing sequence, the operator may desire to auto prime the servicingapparatus 20. This feature is used to purge air out of the system.Preferably, at least six quarts of new fluid must be present in the newfluid tank 42 to initiate this procedure. After ensuring the properfluid level in the new fluid tank, the operator connects one end of eachservicing hose 44 and 46 to the respective return and exhaust ports 34,32 and connects the free ends of the hoses together with a priming hose(not shown) to complete the circulation loop. The operator then selectsOP7 by toggling the options menu button 142 and then depresses the startbutton 144. During the auto prime procedure, the controller 28 willactuate the pump 24 to begin drawing fluid from the new fluid tank 42through the supply path 93 and expelling fluid through the exhaust port32. The expelled fluid is transferred through the servicing hoses 46 and44 and interconnecting priming hose (not shown) to the return port 34.During this fluid transfer the controller 28 cycles the drain/bypassvalve 70 between first and second positions 66 and 68, respectively tobuild up bursts of pressure to purge unwanted air in the servicingapparatus 20. Once three quarts of fluid have been transferred to theused fluid tank 40, the procedure is terminated by the controller 28.Such procedure is typically initiated prior to a fluid exchange.

Referring now to FIGS. 2 and 6, another set of features engageablethrough the control panel 130 include filling the and drainingtransmission pan without removing the pan. In order to perform a quickfill of the transmission pan, the servicing hose 46 is connected betweenthe exhaust port 32 and an interrupted influent cooling line or fillingport of the transmission. The operator may then select OP1 using theoptions menu button 142 and depress the start button 144 to initiate theprocess. The controller 28 energizes the dump/supply valve 84 to thesupply position 81 and actuates the pump 24 to transfer fluid from thenew fluid tank 42 in a one quart increment to the transmission (FIG.11).

To drain the transmission pan, the servicing hose 44 is connectedbetween the return port 34 and an interrupted effluent transmissioncooling line or outlet. OP2 is selected by the operator using theoptions menu button 142 and the operator may then depress the startbutton 144. Drain/bypass valve 70 is energized by the controller 28 todrain position 66 establishing an open drain path 57 (FIG. 10). Theoperator may then turn the vehicle ignition on to start the transmissionpump forcing fluid out through the transmission effluent line and intothe return port 34 through the drain path 57, in the direction indicatedby arrow 58, to be collected in the used fluid tank 40. Once a quart hasbeen removed as detected by the used fluid level sensor 102 anddetermined by the processor 28, the complete indicator 164 on thecontrol board illuminates alerting the operator to terminate theprocedure.

Two other options may be used to check the new and used fluid sensors100 and 102, respectively. To access the new fluid sensor check, theoperator may access the options menu 132 by depressing the options menubutton 142 until OP8 is displayed in the counter display 136. Theoperator then depresses the start exchange/options button 144. The newfluid level sensor 100 will transmit a signal to the controller 28corresponding to the fluid volume in the new fluid tank 42. An absolutereading, which is typically between 300 and 4096 fluid units, will bedisplayed on the display counter 136. The start button 144 is thendepressed again to zero the absolute reading. A measured quantity of newfluid such as one quart is poured into the new fluid tank 42 through thefill hole. A new reading corresponding to the amount of fluid pouredinto the new fluid tank is measured by the processor 28 via the newfluid sensor 102 and displayed on the counter display 136. For example,if one quart is added, the counter display 136 should read 78 fluidunits. Any other reading indicates the sensor may need to be replaced orrecalibrated.

A similar procedure may be used to check the used fluid level sensor102. In this scenario, the operator selects OP9 in the display counter136 using the options menu button 142 and depresses the start button144. An absolute reading is displayed and then zeroed by depressing thestart button 144 again. A known quantity of fluid is poured into theused fluid tank 40 which is measured by the used fluid level sensor 102and displayed on the display counter 102. If the quantity displayed doesnot correspond to the amount poured in then the operator is alerted thatthe used fluid sensor may need to be replaced or recalibrated.

Another convenient feature programmed into the controller 28 is thetotalizer. Such feature keeps track of the number of fluid units passingthrough the servicing apparatus 20. The total amount may be displayed inthe display counter 136. As the display counter may only display acertain number of digits, a separate rollover counter is displayedindicating how many times the counter has reached its numerical limit.For example, if two digits were dedicated to the totalizer display, adisplay reading of “2” is displayed initially and is followed by a “78”.Such display indicates the servicing apparatus has circulated 278 quartsof fluid. Advantageously, this feature enables the operator to develop amaintenance or replacement plan for the servicing apparatus 20 and itscomponents. This feature is accessible through depressing the stopbutton 188 for approximately 5 seconds.

The capability for smaller increment level adjustments is alsoconveniently built into the servicing apparatus 20. For example, ifduring an exchange operation, the operator elects to top off thetransmission fluid level with the hose 46 connected between the exhaustport 32 and the transmission influent line or inlet, the operator maydepress the add ATF button 182 on the control panel 130 (FIG. 2). Inresponse, the controller 28 commands the dump/supply valve 84 to thesupply position 81 and further commands the pump 24 to actuate such thata predetermined amount of new fluid is transferred along the supply pathto the transmission (FIG. 11). It has been found that about 2/10 of aquart is a sufficient amount for such incremental fluid transfersalthough it will be appreciated that other suitable levels may be used.Once the predetermined amount has been removed from the new fluid tank42, the controller 28 shuts the pump 24 off to terminate the transfer.

To withdraw a relatively small increment of used fluid from thetransmission, the operator selects the remove ATF button 184 on thecontrol panel 130 while the vehicle transmission is running and the hose44 is connected between the return port 34 and the transmission effluentline or outlet (FIGS. 2 and 10). The controller 28 will then command thedrain/bypass valve 70 to assume the drain position 66 such that usedfluid is transferred from the transmission under the pressure of thetransmission pump through the return port 34 to the used fluid tank 40in the direction of arrow 58 through the drain path 57 upon turning thevehicle engine on. Once a 2/10 of a quart or other predeterminedincrement is added to the used fluid tank 40, the controller 28 actuatesthe valve 70 to bypass position 68 to direct the fluid through thebypass/recirculation pathway 80.

It will be appreciated that the present embodiment is designed to detectreverse flow without harming the apparatus, transmission, or operator,and to prevent fluid exchange until the fluid flow is conducted in adirection wherein the effluent flow from the transmission passes intothe return port 34 and the influent flow to the transmission comes fromthe exhaust port 32. While such features have been provided in theservicing apparatus 20 to minimize operator intervention and facilitatemaintenance of the servicing apparatus and alert the operator to errorconditions, as discussed above, it is contemplated that an operator mayon occasion inadvertently couple the service hoses 44 and 46 between thetransmission and servicing apparatus 20 incorrectly thus creating areverse fluid circulation condition. While this may be adequatelyhandled as described above with an alert to the operator, other ways ofhandling this condition are also contemplated by the present invention.

Cross Flow Operation

As discussed above, it is foreseeable that an operator may inadvertentlyconnect the hoses 44 and 46 improperly and upon initiating an exchangeprocedure, a switch hoses indicator 166 would illuminate on the controlboard 130 to alert the operator to the error condition indicating thatfluid is flowing in a direction opposite to direction of arrow 59. Theoperator may then turn the engine off and manually switch the hoses 44and 46 by disconnecting and reconnecting them to the proper return andexhaust ports 34 and 32. The technician may then restart the vehicle andinitiate the fluid exchange as described above.

Referring now to FIG. 7, wherein like components are like numbered, asecond exemplary embodiment of the present invention includes analternative manifold body 231 for avoiding the necessity of manuallyswitching the hoses 44 and 46. In general, this alternative embodimentis constructed the manner as the first manifold body 31 described abovewith the exception that an alternative valve 270 has been substituted inplace of the drain/bypass valve 70 of the first embodiment. Suchalternative valve 270 is preferably a 3-position, 4-way, magneticsolenoid valve with cross flow capabilities. The crossflow valve 270includes a normal fluid exchange position, indicated by directionalarrows 272, a bypass position, indicated by a U-shaped symbol 274, and across flow fluid exchange position, indicated by directional arrows 276.

With continued reference to FIG. 7, when energized to the normal fluidexchange position 272 by the processor 28, used fluid entering thereturn port 34 is transferred to the used fluid tank 40 and new fluidwithdrawn from the new fluid tank 42 may be transferred to the exhaustport 32 in a manner similar to that described above in the firstembodiment. This is effectively the same as the fluid exchange flowalong the drain path 57 and supply path 93 as in the first embodiment asillustrated in FIGS. 6, 9, and 11.

If, however, the controller 28 energizes the alternative valve 270 tothe bypass position 274, the servicing apparatus 20 is placed in abypass/recirculation mode similar to the recirculation path 80illustrated in FIG. 8. Thus fluid may be circulated between thetransmission and servicing apparatus as described above with servicehoses 44 and 46 connected between the return port 34, exhaust port 32and transmission influent and effluent lines. Fluid being circulatedduring this mode may circulate in either direction as determined by theflow from the transmission.

Referring now to FIGS. 2, 7, and 13–14, in those instances where theoperator has incorrectly coupled the servicing hoses 44 and 46 to theservicing apparatus 20 so that used fluid enters through the exhaustport 32 instead of the return port 34 and the start button 144 on thecontrol panel 130 is depressed, the controller 28, upon receiving asignal that no fluid is entering the used fluid tank 40 and detectingfluid pressure via the pressure sensor 108, reacts accordingly byenergizing the crossflow valve 270 to assume its cross flow position276. As shown in FIGS. 7 and 14, in this position, it will beappreciated that fluid entering through the exhaust port 32 will bedirected through the solenoid 270 to cross over to the drain path,generally designated 257, to flow in the direction indicated by arrow258, where the used fluid may then be expelled through drain port 36 tobe collected in the used fluid tank 40. In such scenario, service hose46 is an inhose and port 32 is an inflow port. Likewise, new fluidsupplied from the pump 24 in the supply path, generally designated 293,to flow in the direction indicated by arrow 261, and passing throughfilter 88 flows through the check valve 92 and cross over valve 270 andis directed to the return port 34 which in this scenario operates as anoutflow port and hose 44 is an outhose (FIGS. 7 and 13). With thesolenoid 270 configured in the cross position 276, normal transmissionfluid exchange procedures may be performed as described for the firstembodiment above. Thus, it will be appreciated that such valve 270enables the operator to connect the hoses 44 and 46 without concern asto the flow direction as determined by the transmission configuration.Once the controller 28 establishes the proper valve position 272, 274,or 276, all servicing procedures may be performed as described above forthe first embodiment.

While the above described embodiments serve particularly well inservicing automatic transmissions, the present invention furthercontemplates servicing other automobile fluid systems as well andprovides such convenience in a single portable wheeled apparatus.

Power Steering Fluid Servicing

For example, referring now to FIGS. 4–5, another embodiment of thepresent invention will now be described. When an automobile is taken infor transmission servicing, it is typically necessary and convenient toexchange the power steering fluid at the same time. Advantageously, thepresent invention may incorporate additional plumbing to facilitate sucha power steering fluid exchange. FIG. 4 illustrates the additionalplumbing for adding fluid to the power steering fluid reservoir (notshown). Such new power steering fluid (PSX) circuit, generallydesignated 200, is a conduit or servicing hose with several inlinecomponents including a new power steering fluid tank 204 preferablyhaving at least a two quart capacity, a new fluid filter 206, and a newpower steering fluid pump 208 in fluid communication with one anotherand terminating at one end in a coupling 210 or free end for insertinginto the open fill hole of the power steering reservoir. An inline ballvalve 223 is provided proximate the hose end to open and close the PSXsupply circuit 220 and prevent residual fluid in the conduit fromleaking out inadvertently.

Turning now to FIG. 5, for removing fluid from the power steeringreservoir, a PSX drain circuit, generally designated 220 is alsoprovided. Such drain circuit is a servicing hose or conduit with severalinline components including a drain pump 222, a used PSX filter 224 andterminating at one end in a coupling 228 or free end for insertion intothe power steering fluid reservoir. An inline ball valve 225 is providedfor opening and closing the drain circuit for similar purposes to ballvalve 223. The other end of the PSX drain circuit is convenientlycoupled to the used fluid tank 40 (FIG. 6) so that one common tank mayaccept either used transmission fluid or used PSX fluid. Such PSX supplypump 208 and PSX drain pump 222 are connected to the controller 28 (FIG.6) which may actuate either pump. The PSX supply and drain pumps mayalso be powered by the battery cable 120 connection to a 12 volt DCpower source such as the vehicle battery.

Referring now to FIG. 2, the operator may depress the power steeringbutton 180 located on the control panel 130 to initiate a power steeringfluid exchange by setting the servicing apparatus 20 in PSX mode.Alternatively, the power steering exchange may be performed using aremote pendant 230 having selection switch means including an “ADD”button 221 and a “DRAIN” button 227 (FIG. 1). Such pendant may bedirectly connected to the controller 28 via suitable electrical cablingor communicate with the controller using wireless technology includingradio frequency or infrared communication. It is further contemplatedthat the ball valves 223, 225 may be coupled to the pendant 230 andremotely actuatable. Conveniently, when not in use, the pendant isreleasably retained on the control panel using a removable magneticholder 229 placed on the control board 130 in the pendant dock region140 (FIGS. 1 and 2).

In operation, and with particular attention to FIGS. 1–2, 4 and 5, toexchange the power steering fluid in the power steering fluid reservoir,the following exemplary procedure may be used. The apparatus 20 isinitially wheeled over near the vehicle and the operator attaches thebattery cables 120 to the vehicle battery providing power to theservicing apparatus 20 and drain and supply pumps 208, 222. The operatormay then depress the power steering button 180 to set the servicingapparatus 20 into power steering fluid exchange mode. “PS” will displayin the display counter 136 on the control board 130 to indicate powersteering mode is engaged. The cap of the power steering reservoir, andany screen, is removed. The operator may then start the vehicle ignitionto start the engine running. The PSX drain coupling 222, which may be anopen hose end is placed inside the power steering reservoir as is thesupply coupling 210, also an open hose end. The hoses are preferablyequal in length and are disposed near the bottom of the power steeringfluid reservoir and are maintained at all times beneath the top fluidlevel in the fluid reservoir. Each ball valve 223, 225, of therespective supply and drain circuits 200, 220 are opened fully.Conveniently, the remote pendant 230 may be removed from its holder 229and held by the operator to extend operator mobility. The magneticholder may then be used to hold the hoses of the drain and supplyconduits in place to prevent the hoses from tangling. With the ballvalves 223, 225 open, the operator depresses the Add and Drain buttons221, 227 on the pendant 230 alternately to repeatedly drain and fill thereservoir while observing the fluid level in power steering fluidreservoir (FIGS. 1, and 4–5). This flushes the old fluid out of thereservoir. With the engine still running, the operator turns thesteering wheel fully to the left and right and then back to the centerand then checks the fluid color in the reservoir. Using the pendantallows the operator to move between the steering wheel and fluidreservoir. The alternating drain and fill step and wheel turning stepare repeated until a satisfactory fluid color is observed. During thisprocess, the processor 28 monitors the used fluid tank 40 level via theused fluid sensor 102. If a used fluid tank overflow condition isanticipated, the processor 28 disables the drain button 227 on thependant, illuminates the used fluid full indicator 172, and sounds analarm.

Once the operator notes the desired fluid color indicating the exchangeis complete, the operator may depress the ADD button 221 on the pendantto top off the power steering fluid reservoir. Alternatively, theoperator may observes bubbles in the power steering fluid reservoirindicating that the new fluid supply has been exhausted. The operatormay then turn off the engine off and replace the cap and screen, if any,on the power steering fluid reservoir. Depressing the power steeringbutton 180 again resets the servicing apparatus to automatictransmission fluid exchange mode. It is apparent that the remote pumpactuator conveniently allows the operator to move back and forth betweenthe vehicle steering wheel and the power steering fluid reservoir asnecessary.

It will be appreciated that system described herein is capable ofperforming a number of operations including draining the used ATF fluidfrom the transmission, adding new ATF fluid to the transmission,draining the used fluid tank, draining the new ATF tank, using a singlecommon pump coupled to a fluid circuit provided by an integratedmanifold assembly constructed to minimize assembly time. Additionalplumbing features may also be introduced to perform cross flowsituations as well as service the power steering reservoir with aservicing apparatus incorporating a minimal amount of components.

The common pump 24 is preferably a one-way 130 psi pump available fromShur-Flo. The power steering drain and fill pumps 208, 220 are alsoavailable from Shur-Flo and of a 45 psi variety. Other suitable pumpvarieties may also be used. The pressure switch is preferably set toabout 6 psi and is available from the Nason Company.

It will be appreciated that the drain path 58 (FIG. 10) between thereturn port 34 and drain port 36 is formed almost entirely within themanifold body as is the recirculation path 59 (FIG. 8) between thereturn port 34 and exhaust port 32. Such paths only exit the manifoldbody to enter filter 60. In addition, much of the dump and supply path61, 63, respectively, lengths are formed within the manifold body 31 aswell with only a relatively short segment extending outside the manifoldbody to pass through the pump 24 or filter 88. Incorporation of a numberof right angles in the pathways is formed using three longitudinallyprojecting bores which are perpendicular from the passages projectingfrom the ports on the rear and top surfaces of the manifold body 31. Thebores ends are plugged during manufacture 192. By forming most of thefluid circuit within the manifold body, the hose length requirements aresignificantly reduced and the drawbacks of using hose segments such asthose caused by high temperatures are effectively removed as well.

While a rigid manifold body having a preformed fluid circuit has beendescribed in these exemplary embodiments, it is contemplated that suchmanifold body could also be a hollow or a partially hollow shellincorporating flexible or rigid conduits internally between the variousports.

While the present invention has been described herein in terms of anumber of preferred embodiments for performing fluid servicingprocedures on a vehicle, various changes and improvements may also bemade to the invention without departing from the scope thereof.

1. A method for exchanging fluid with an automobile having a steeringwheel and a power steering fluid reservoir having an upper fluid level,the method comprising: providing a used fluid receptacle and a freshfluid source in a portable wheeled cabinet; coupling a first end of adrain conduit to said used fluid receptacle, said drain conduitincluding a drain pump and a first extension terminating in a first freeopposing end; coupling a first end of a supply conduit to said freshfluid source, said supply conduit including a supply pump and a secondextension terminating in a second free opposing end; providing a remotepump actuating means coupled to said drain and supply pumps andincluding selection switch means for operably actuating either of saidpumps; placing said free ends of said first and second extensions insaid power steering fluid reservoir and extending said fluid freeopposing end to the bottom said reservoir; grasping said remote pumpactuating means and alternately actuating said drain and supply pumpwith said selection means to repeatedly drain and fill said powersteering fluid reservoir to provide replacement fluid therein whileholding said remote pump actuating means; and rotating said steeringwheel of said automobile to a full extent in a first direction and thento a full extent in the opposite direction while holding said remotepump actuating means, observing the replacement fluid; repeating saidalternately actuating and rotating steps and continuing to observe saidreplacement fluid in said reservoir until it is made up of substantiallyonly fresh fluid while holding said remote pump actuating means.
 2. Themethod for exchanging fluid as set forth in claim 1 further comprising:providing a first flow control means in said drain conduit for openingand closing said drain conduit; and opening said drain conduit with saidfirst flow control means prior to actuating said drain pump.
 3. Themethod for exchanging fluid as set forth in claim 1 further comprising:providing a second flow control means in said supply conduit for openingand closing said supply conduit; and opening said supply conduit withsaid second flow control means prior to actuating said supply pump. 4.The method for exchanging fluid in an automobile having a steering wheeland a power steering fluid reservoir containing uses power steeringfluid of one color indicative of the fact it is used, the methodcomprising: placing a portable housing adjacent said power steeringfluid reservoir, said housing including a used power steering fluidreceptacle and a fresh power steering fluid source containing a freshpower steering fluid of a second color different than said one color;placing a first free end associated with a drain conduit into said usedpower steering fluid is said power steering fluid reservoir, said drainconduit comprising a first segment connecting said first free end to adrain pump and a second segment connecting said drain pump to said usedpower steering fluid receptacle; placing a second free end associatedwith a supply conduit into said power steering fluid reservoir, saidsupply conduit comprising a first segment connecting said second freeend to a supply pump and a second segment connecting said supply pump tosaid fresh power steering fluid source; operating a hand-held remotepump actuator linked to said drain pump and to said supply pump saiddrain pump to withdraw used fluid from said power steering fluidreservoir through said first free end to said used power steering fluidreceptacle, then actuating said supply pump to add fresh fluid from saidfresh power steering fluid source through said second free end to saidpower steering fluid reservoir and observing color of the steering fluidin the reservoir; rotating said steering wheel of said automobile to afull extent in a first direction and then to a full extent in theopposite direction while holding said hand-held remote pump actuator,repeating said operating step, said rotating step and said observingstep repeatedly until the fluid observed in said reservoir reaches acolor indicating said used fluid has been substantially replaced byfresh power steering fluid while holding said hand-held remote pumpactuator.